New Covid vaccine mimics virus shape to provide robust protection: Study
PTI, Aug 14, 2021, 10:30 AM IST
Credit: iStock Photo
Washington DC: Scientists have developed a protein-based COVID-19 vaccine candidate that mimics the shape of the virus to trigger robust antibody response in animals.
In the study published in the journal ACS Central Science, the researchers immunized mice with nanoparticles that mimic SARS-CoV-2, the virus that causes COVID-19, by displaying multiple copies of the receptor-binding domain (RBD) antigen.
Most protein-based vaccines train the immune system to recognize the RBD, a portion of the SARS-CoV-2 spike protein, which the virus uses to enter and infect human cells.
The spike protein binds to the ACE-2 receptor on host cell surfaces, which acts as a gateway for the entry of the virus.
However, not all vaccines elicit both antibody and T cell responses, both of which are thought to be important for longer-lasting immunity.
The researchers from the University of Chicago, US, had previously developed a vaccine delivery tool called polymersomes — self-assembling, spherical nanoparticles that can encapsulate antigens and adjuvants — and then release them inside immune cells.
Adjuvants are helper molecules that boost the immune response.
Polymersomes trigger robust T cell immunity, the researchers said.
The team wondered if they could further improve the antibody response by engineering the nanoparticles to mimic viruses by displaying multiple copies of the RBD on their surfaces.
The researchers made polymersomes that were similar in size to SARS-CoV-2 and decorated them with many RBDs.
After characterizing the nanoparticles in a lab, they injected them into mice, along with separate polymersomes containing an adjuvant, in two doses that were three weeks apart.
For comparison, they immunized another group of mice with polymersomes that encapsulated the RBD, along with the nanoparticles containing the adjuvant.
Although both groups of mice produced high levels of RBD-specific antibodies, only the surface-decorated polymersomes generated neutralizing antibodies that prevented SARS-CoV-2 infection in cells.
Both the surface-decorated and encapsulated RBDs triggered robust T cell responses, the researchers said.
Although the new vaccine still needs to be tested for safety and efficacy in humans, it could have advantages over mRNA vaccines about widespread distribution in resource-limited areas, they said.
That is because the surface-decorated polymersomes are stable and active for at least six months with refrigeration, the researchers said.
In contrast, mRNA vaccines require subzero temperature storage, they added.
Udayavani is now on Telegram. Click here to join our channel and stay updated with the latest news.
Top News
Related Articles More
Risk of abnormal blood fat levels increased by about 30 pc during pandemic, finds study
Attention problems could be ‘middleman’ between genetic risk for, experiencing psychosis: Study
Meeting WHO’s sodium recommendations could avert deaths from heart, kidney disease: Study
Meeting WHO’s sodium recommendations could avert deaths from heart, kidney disease: Study
Study finds loss of smell linked with inflammation in 140 conditions, could be early sign of disease
MUST WATCH
Latest Additions
Balasore tragedy result of composite negligence of railway officials: Orissa High Court
Actress Kasthuri stokes controversy by her remarks on Telugu-speaking people in TN
Three convicted for 2016 Kollam collectorate blast case
Expect Canadian government to ensure justice, uphold rule of law: PM Modi
Group clash in Indore after argument over bursting firecrackers: NSA slapped against 2 accused
Thanks for visiting Udayavani
You seem to have an Ad Blocker on.
To continue reading, please turn it off or whitelist Udayavani.